(1) Field of the invention
The present invention relates to detection or warning devices for detecting and providing indication of changes in attitude or inclination of a body or mass, however slowly such change in attitude or angle of inclination may occur. In particular, the invention includes a piezo-electric device which is attached to a body or mass and actuated when the attitude or inclination of the body changes.
In the process of removing wheels and/or tires from a motor vehicle, whether authorized or not, it is usual to lift one side or one end of the vehicle, as opposed to lifting the whole vehicle. In the process of lifting or raising one side or one end of a vehicle the attitude or angle of inclination of the vehicle changes. This change in attitude is viewed as a relatively slow change. As an antitheft system, the present invention responds to a change in attitude such as described above and, if a change in attitude is created by an unauthorized lifting of a part of the vehicle, an alarm would warn the owner that his vehicle is being attended, and if unauthorized, is in all probability having an act of theft committed upon it.
(2) Prior Art
In the past, warning and/or detection devices using piezo-electric devices or transducers were limited to the detection of vibrations of the body or mass to which the transducer is attached or the detection of breakage or removal of the transducer from the body.